Establishing Paternity in Knox County

Reviewed by Stephanie Green · Managing Partner & Co-Founder · Last updated June 11, 2026

Knox County, Ohio · Mount Vernon

Paternity legally establishes a child's father, which is the step that lets the court order custody, parenting time, and child support for an unmarried couple. In Knox County, parentage cases are heard in the Probate & Juvenile Court (Judge Jay W. Nixon), and Knox County Child Support Services can establish paternity administratively.

How do I establish paternity in Knox County, Ohio?

Paternity can be established three ways: by signing an Acknowledgment of Paternity (at the hospital or later through the CSEA), by an administrative order through Knox County Child Support Services, or by a court parentage case with genetic testing in the Knox County Probate & Juvenile Court (111 East High Street, 1st Floor, (740) 393-6798). A new parentage/custody/support complaint in that court is $300. Once paternity is established, the court can set custody, parenting time, and child support using the Ohio Income Shares worksheet.

Ohio Custody by the Numbers

Best interest The single standard that governs every Ohio custody decision Source: Ohio Revised Code § 3109.04
No set age There is no age a child can choose a parent — the judge weighs a mature child's wishes Source: Ohio Revised Code § 3109.04(B)
Change in circumstances Required, plus a best-interest finding, before the residential parent can be changed Source: Ohio Revised Code § 3109.04(E)(1)
Shared parenting Either parent may ask the court for a joint parenting plan Source: Ohio Revised Code § 3109.04(G)

Compare Types of Custody in Ohio

Custody type	Who makes major decisions	Where the child lives	Best when
Shared parenting	Both parents jointly, under a written plan	Time is split per the plan (not always 50/50)	Parents can communicate and cooperate on decisions
Sole legal & residential	One parent	Primarily with that parent	One parent is unable or unwilling to co-parent
Split custody	Each parent for the child in their care	Siblings are divided between the two homes	Rare — only when it serves each child's best interest
Legal custody to a non-parent	The relative or caregiver granted custody	With the non-parent caregiver	Neither parent can safely care for the child

Where to File: Knox County Court of Common Pleas — Domestic Relations Division

111 East High Street, 2nd Floor, Mount Vernon, OH 43050
Phone: (740) 393-6777
Hours: Monday–Friday (confirm current hours with the Clerk of Courts at (740) 393-6788)
Website: co.knox.oh.us/common-pleas/

Juvenile Branch (Never-Married Parents)

Knox County Probate & Juvenile Court
111 East High Street, 1st Floor, Mount Vernon, OH 43050
Phone: (740) 393-6798
Hours: Monday–Friday (confirm current hours with the court at (740) 393-6798)

Paternity is the right path if…

The parents were never married to each other and need to establish the child's legal father.
You want a court order for custody, parenting time, or child support that depends on paternity being established first.
You're willing to sign an Acknowledgment of Paternity, or to ask for genetic testing if paternity is disputed.
Ohio is the child's home state under the UCCJEA — the child has lived in Ohio for the last 6 months.

Filing Fees

$300 new parentage/custody/support case in the Probate & Juvenile Court · $200 reopen on an existing case · fee waiver via an Affidavit of Indigency · CSEA can establish paternity administratively. Confirm amounts with the court at (740) 393-6798.

Forms & Filing Packets

Court parentage case (Probate & Juvenile Court) — $300 new parentage/custody/support case

File a parentage complaint in the Knox County Probate & Juvenile Court; the court can order genetic testing and then allocate custody, parenting time, and support.

Parenting Proceeding Affidavit (UCCJEA · R.C. 3127.23) — Lists where each child has lived for the last 5 years and with whom, confirming Ohio's jurisdiction over custody under the UCCJEA. Required in any case involving minor children.
Complaint for Allocation of Parental Rights & Responsibilities (Ohio SC Form 23) — Asks the Juvenile Branch to name a residential parent and legal custodian and set a parenting-time schedule when the parents were never married.
Ohio Child Support Computation Worksheet (2024 Income Shares) — Run the official Ohio Child Support Calculator, print, and sign. Required any time the court sets or changes support.
Apply for Child Support Services (Title IV-D) — Knox County CSEA — Opens a IV-D child-support case with Knox County Child Support Services. Once opened, CSEA establishes/collects support by income withholding and can enforce it. Phone (740) 397-7177 ext. 3040 or (800) 298-2223.

How to File Paternity in Knox County

Choose how to establish paternity. Use an Acknowledgment of Paternity or a CSEA administrative order if both parents agree, or file a court parentage case if paternity is disputed.
File in the Probate & Juvenile Court. File the parentage complaint and the Parenting Proceeding Affidavit (UCCJEA) in the Knox County Probate & Juvenile Court, and pay the $300 deposit (or file an Affidavit of Indigency).
Complete genetic testing if ordered. If paternity is disputed, the court orders genetic testing before it establishes parentage.
Set custody and support. Once paternity is established, the court allocates custody and parenting time and sets child support on the Ohio Income Shares worksheet; open a IV-D case with CSEA to collect support.

Knox County Practice Notes

Three ways to establish paternity. Paternity can be established by an Acknowledgment of Paternity (signed at the hospital or through CSEA), by an administrative order through Knox County Child Support Services, or by a court order with genetic testing in the Probate & Juvenile Court. The court route is used when paternity is disputed.
Paternity comes before custody and support. For never-married parents, the court can only allocate custody, parenting time, and child support once paternity is legally established. Filing the Parenting Proceeding Affidavit (UCCJEA) confirms Ohio's jurisdiction over the child.

Frequently Asked Questions

How is paternity established in Knox County?: Paternity can be established three ways: by signing an Acknowledgment of Paternity (AOP) at the hospital or later through the CSEA, by an administrative order through Knox County Child Support Services, or by a court order with genetic testing in the Probate & Juvenile Court. Establishing paternity is the legal step that lets the court order custody, parenting time, and child support for an unmarried couple's child.
What does it cost to file a parentage or custody case in the Knox County Probate & Juvenile Court?: For never-married parents, a new complaint or motion to establish paternity, support, or custody in the Probate & Juvenile Court is $300, and a reopened or new action on an existing case is $200. If you cannot afford the deposit, an Affidavit of Indigency (fee waiver) is available. Confirm the current amounts with the Probate & Juvenile Court at (740) 393-6798.
Which Knox County court hears my family-law case?: If you are (or were) married to the other parent, divorce, dissolution, legal separation, annulment, post-decree matters, and civil protection orders are heard in the Domestic Relations Division of the Knox County Court of Common Pleas (Judge Richard D. Wetzel; Magistrate Natasha Plumly), and filed with the Clerk of Courts at 117 East High Street, Suite 201, Mount Vernon. If you were never married, parentage, custody, parenting time, and child support — and all non-parent custody requests — are heard in the Knox County Probate & Juvenile Court (Judge Jay W. Nixon), 111 East High Street, 1st Floor, (740) 393-6798.
What does the Knox County CSEA do, and do I need a IV-D application?: Knox County Child Support Services (the CSEA) is the IV-D agency that establishes, collects, and enforces child support. Filing a IV-D Application opens a support case so CSEA can set support under Ohio's guidelines, collect by automatic income withholding, distribute payments, and enforce orders through wage withholding, license suspension, tax intercept, and contempt referrals. Reach CSEA at (740) 397-7177 ext. 3040 or (800) 298-2223.
What are the residency requirements to file in Knox County?: To file for divorce, dissolution, or legal separation, the plaintiff (or one spouse, for a dissolution) must have been an Ohio resident for at least 6 months before filing (R.C. 3105.03) and meet county venue under Civil Rule 3. The Knox County rules do not set a separate minimum county-residency period. For never-married custody in the Probate & Juvenile Court, Ohio must be the children's 'home state' under the UCCJEA (R.C. 3127) — generally, the children have lived in Ohio for the last 6 consecutive months.

Free Local Resources in Knox County

Knox County Clerk of Courts (Domestic Relations). Where divorce, dissolution, legal-separation, and post-decree filings are made — 117 East High Street, Suite 201, Mount Vernon, (740) 393-6788. The Clerk confirms current deposits and packet requirements; the Fee Schedule (effective 9/26/2025) and DR Rules are posted at https://co.knox.oh.us/common-pleas/.
Knox County Probate & Juvenile Court. Hears never-married parentage, custody, support, and non-parent custody, plus adoption — 111 East High Street, 1st Floor, Mount Vernon, (740) 393-6798. New parentage/custody/support case $300; reopen $200. Local rules at https://knoxpjcourt.com/.
Knox County Child Support Services (CSEA). The IV-D agency that establishes, collects, and enforces child support by income withholding. Apply for services at https://co.knox.oh.us/jfs/child-support/ or call (740) 397-7177 ext. 3040 or (800) 298-2223.
Parenting Wisely seminar. The court-ordered parenting-education seminar for any divorce, dissolution, legal separation, or annulment with minor children — about 2 hours, $30 cash or money order payable to the Knox County Treasurer, due within 45 days of filing (DR Rule 12).
Ohio Child Support Calculator. Run the official Ohio 2024 Income Shares child-support worksheet at https://ohiochildsupportcalculator.ohio.gov/ before any case that sets or changes support.

Related to your paternity case

Child Support — Calculate, establish, or modify support under Ohio's guidelines.
Grandparents' Rights — Seek visitation or custody when it serves the child's best interest.
Post-Decree Modification — Update custody, support, or parenting orders after your case ends.

Related guides

In-depth, attorney-written guides on paternity and related Ohio family law topics.

Fathers' Rights in Ohio: Custody, Paternity, and Parenting Time — Ohio law does not favor mothers over fathers — but unmarried fathers must establish paternity before they have any rights. Here's how fathers protect their relationship with their children.
Ohio Child Custody Laws: What Every Parent Should Know — Ohio custody law turns on one principle: the best interest of the child. This guide explains sole custody, shared parenting, the statutory factors, and how courts decide.
Child Support Calculation in Ohio: How the Formula Works — Ohio calculates child support with the income shares model, combining both parents' incomes to set a shared obligation. Here's how the formula works and what changes the bottom line.

Keep exploring

Ohio Paternity guide — Statewide overview of paternity in Ohio.
Columbus family law — Local attorneys and courts serving the Columbus metro.
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